Calendar Alarm D-DAY is a free Android application developed by OK soft, which falls under the category of Utilities & Tools. This app is designed to help users set reminders for important events or dates. With the app, users can select a desired date from the calendar and set an alarm to remind them of the event.

One of the best features of this app is the widget that allows users to see their schedule at a glance. This widget can be placed on the home screen of the device and provides a quick and easy way to view upcoming events. Overall, Calendar Alarm D-DAY is a useful app for anyone who wants to stay organized and never forget an important date.